• Journal of Life Science
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• v.33 no.3
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• pp.277-286
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• 2023

Sarcopenia is the age-related loss of muscle mass and function. It is a natural part of aging and can lead to decreased mobility and increased frailty. The ubiquitin-proteasome pathway, which is involved in muscle protein degradation, is closely linked to sarcopenia. Germinated Rhynchosia nulubilis hydrolysate (GRH) has been reported to have anti-inflammatory and antioxidant properties, but there have been no reports on its inhibitory effect on muscle reduction. However, no study has yet explored the relationship between GRH and muscle loss inhibition. In this study, we evaluated the effects of GRH on muscle atrophy inhibitory activity in dexamethasone (Dexa)-induced muscle atrophy C2C12 myotubes and mouse models. Moreover, we identified a molecular pathway underlying the effects of GRH on skeletal muscle. May Grunwald-Giemsa staining showed that the length and area of myotubes increased in the groups treated with GRH. In addition, the GRH-treated group significantly reduced the expression of muscle ring finger protein 1 and muscular atrophy F-box (MAFbx) in the Dexa-induced muscular atrophy C2C12 model. GRH also improved muscle strength in C57BL/6 mice with Dexa-induced muscle atrophy, resulting in prolonged running exhaustive time and increased grip strength. We found that muscle strengthening by GRH was correlated with a decreased expression of the MAFbx gene in mouse muscle tissue. In conclusion, GRH can attenuate Dexa-induced muscle atrophy by inhibiting the ubiquitin-proteasome pathway via downregulation of the MAFbx gene expression.

• Journal of The Korean Association For Science Education
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• v.43 no.1
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• pp.1-15
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• 2023

As the social and economic value of living modified organisms (LMOs) increase, so do the potential risks they pose to humans and the environment. Therefore, all laboratories using LMOs must establish an LMO laboratory in accordance with the standards required by regulations. Recently, in high school, LMO-related experimental programs have been developed for their educational effects. Also, in this case, it is necessary to comply with the regulation for LMO laboratories. However, high schools are still unfamiliar with the LMO laboratory, and it is difficult for teachers to manage an LMO laboratory because its implementation applies the same standards to general research institutes. In this study, we used causal chain analysis to discover the difficulties each teacher faced while setting up an LMO laboratory by examining three cases. The difficulties experienced by teachers are as follows: the first problem is "reluctance to set up an LMO laboratory," because of "administrative tasks for laboratory registration" and "difficulty in persuading colleagues." The second problem is a difficulty for teachers to operate LMO laboratory in blind spots, due to "inflexible installation and closure," "medical waste disposal," and "LMO education that does not fit the school context." Through this study, although the difficulty of running an LMO laboratory is caused by a lack of necessity and insufficient consideration of the school context, the more fundamental cause was a lack of collaborative planning between the educational field and the operating institutions. The teachers who participate in this research suggest that "using shared LAB" and "preparing opportunities for knowledge sharing" can be considered as strategies for operating the school's LMO laboratory. We feel that this study will provide a useful reference for teachers or schools planning to build an LMO laboratory.

• Journal of Service Research and Studies
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• v.10 no.4
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• pp.1-19
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• 2020

It is very important to explore new management theories that are better in line with the modern service economy era in order to cement the foundation of the service industry in this rapidly changing business environment. This study examined the relationship between service essentials and job performance by service industry, and verified and discussed in depth whether there is difference between service essentials and job performance by demographic characteristics. The results of this study are as follows: First, an analysis of the effect of service essentials on job performance found the interaction, horizontality and harmony of service essentials had positive effects on performance, but the relationship didn't. Next, an analysis of the effect of service essentials on job performance by representative service industry showed that in the transportation industry, interaction and harmony had positive effects on performance, but relationship and horizontality didn't affect performance. In the financial and insurance industries, horizontality and interaction had positive effects on performance, but harmony and relationship didn't affect performance. Accommodation and food industries, interaction, horizontality and harmony had positive effects on performance, but relationship didn't affect performance. In the medical and health industries, interaction and horizontality had positive effects on performance, but relationship and harmony didn't affect performance. In terms of demographic characteristics, in the financial and insurance industries, interaction and harmony showed a significant difference by age, but only horizontality showed a difference by the number of years of service. In the accommodation and food industries, only horizontality showed a difference depending on the number of years of service. In the medical and health industries, relationship, horizontality and harmony showed a difference depending on the number of years of service, but only horizontality showed a significant difference by marital status. In the future, comparative national studies are needed for all industrial groups.

• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.651-661
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• 2022

Plants social network analysis, which combines plants society and social network analyses, is a new research method for understanding plants society. This study was conducted to investigate the relationship between species, using plant social network analysis targeting Taejongdae in Busan, and build basic data for management. Taejongdae, located in the warm temperate forest in Korea, is a representative coastal forest of Busan Metropolitan City, and the Pinus thunbergii-Eurya japonicacommunity is widely distributed. This study set up 100 quadrats (size of 100m²each) in Taejongdae to investigate the species that emerged and analyzed the interspecies association focusing on major species. Based on the results, a sociogram was created using the Gephi 0.9.2, and the network centrality and structure were analyzed. The results showed that the frequency of appearance was high in the order of P. thunbergii, E. japonica, Quercus serrata, Sorbus alnifolia, Ligustrum japonicum, and Styrax japonicusand that many evergreen broad-leaved trees appeared due to the environmental characteristics of the site. The plants social network of Taejongdae was composed of a small-scale network with 50 nodes and 172 links and was divided into 4 groups through modularization. The succession sere identified through a sociogram confirmed that the group that include P. thunbergiiand E. japonicawould progress to a deciduous broadleaf community dominated by Q. serrataand Carpinus tschonoskii, using hub nodes such as Prunus serrulataf. spontaneaand Toxicodendron trichocarpum. Another succession sere was highly likely to progress to an evergreen broad-leaved community dominated by Machilus thunbergiiand Neolitsea sericea, using M. thunbergiias a medium. In some areas, a transition to a deciduous broad-leaved community dominated by Celtis sinensis, Q. variabilisand Zelkova serratausing Lindera obtusilobaand C. sinensisas hub nodes was expected.

• Korean Journal of Environment and Ecology
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• v.36 no.6
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• pp.553-565
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• 2022

Awareness of the ecological value and importance of protected areas has increased as climate change accelerates, and there is a need for research on ecosystem services provided by nature. The natural park, which is a representative protected area in Korea, has a system of national parks, provincial parks, and county parks. National parks are managed systematically by the Korea National Park Service, but local governments manage provincial parks and county parks. There may be the same hierarchical differences in naturalness (habitat quality) depending on the hierarchy of the natural parks, but it has not been verified. To identify differences, we examined 22 mountain-type natural parks using habitat quality using the INVEST model developed by Stanford University. The analysis of the habitat quality, regardless of the type and area of the natural park, showed that it was higher in the order of Taebaeksan National Park (0.89), Juwangsan National Park (0.87), Woongseokbong County Park (0.86), and Gayasan National Park (0.85). The larger the area, the higher the value of habitat quality. A comparison of natural parks with similar areas showed that the habitat quality of national parks was higher than that of provincial parks and parks. On the other hand, the average habitat quality of county parks was 0.83±0.02, which was 0.05 higher than that of provincial parks at 0.78±0.03. Furthermore, the higher the proportion of forest areas within the natural park, the higher the habitat quality. The results confirmed that the naturalness of natural parks was independent of their hierarchy and that there are differences in naturalness depending on land use, land coverage, and park management.

• Journal of Bio-Environment Control
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• v.32 no.2
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• pp.97-105
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• 2023

Concentration of nitrogen, one of the major elements, and ratio of two nitrogen forms (NH₄⁺ and NO₃^-) in the nutrient solution affect the quality and food safety of fresh vegetable produce. This study was conducted to find an appropriate strength and NH₄⁺:NO₃^- ratio of a nutrient solution for growth and development of a Romaine lettuce (Lactuca sativa L. var. longiflora) 'Caesar Green', a representative leafy vegetable, grown in a home hydroponic system. In the first experiment, plants were grown using three types of nutrient solution: A commercial nutrient solution (Peters) and two strengths (GNU1 and GNU2) of a multipurpose nutrient solution (GNU solution) developed in a Gyeongsang National University lab. Plants grown with the GNU1 and GNU2 had greater shoot length, leaf length and width, and biomass yield than Peters. On the other hand, the root hairs of plants grown with Peters were short and dark in color. Tissue NH₄⁺ content in the Peters was higher than that of the GNU1 and GNU2. The higher contents of NH₄⁺ in this solution may have caused ammonium toxicity. In the second experiment, eight treatment solutions, combining GNU1 and GNU2 solutions with four ratios of NO₃^- :NH₄⁺ named as 1, 2, 3 and 4 were used. Both experiments showed more growth in the GNU2 group, which had a relatively low ionic strength of the nutrient solution. The growth of Romaine lettuce showed the greatest fresh weight along with low tissue NO₃^- content in the GNU2-2. This was more advantageous in terms of food safety in that it suppressed the accumulation of surplus NO₃^- in tissues due to the low ionic trength of the GNU2 subgroup. In addition, this is preferable in that it can reduce the absolute amount of the input of inorganic nutrients to the nutrient solution.

• Journal of agricultural medicine and community health
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• v.48 no.2
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• pp.132-143
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• 2023

Objectives: We aimed to describe the reporting patterns of 6 notifiable surveillance diseases in the Republic of Korea, including water- and foodborne infections, from 2012 to 2021. Methods: For the 12,296 cases that met the reporting criteria, we calculated the number of reported cases, including the number of cases confirmed by lab tests or suspected by a physician, the number of cases with delayed reporting and their average days of delay, and the median days required to report the confirmatory test results. Results: The overall number of reported cases consistently increased over the ten years, with a significant rise in the reported cases of typhoid fever, paratyphoid fever, and EHEC. Ninety-five percent of all reported cases were timely reported within one day of diagnosis. Vibrio vulnificus had the highest rate of delayed reporting (6.8% delayed over 1 day, 3.0% delayed over 3 days), while cholera had the lowest rate (1.9% delayed over 1 day, 0.1% delayed over 3 days). The average days of delayed reporting was 6.1 days: the highest for paratyphoid fever (10.8 days) and the lowest for cholera (2.7 days). For typhoid fever and paratyphoid fever, there has been an increase in the proportion of cases with negative test results. For vibrio vulnificus, there has been an increase in the proportion of cases with confirmed positive test results. As for EHEC, there has been a recent increase in cases with no confirmatory tests. Conclusions: Reported cases of water- and foodborne infectious diseases increased, indicating improved surveillance system completeness. However, for paratyphoid fever, improvements are needed in terms of timely notification by healthcare facilities and timely reporting of confirmatory test results.

• Journal of Korea Water Resources Association
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• v.56 no.1
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• pp.53-62
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• 2023

Recently, due to the influence of climate change, the occurrence of damage to heavy rain is increasing around the world, and the frequency of heavy rain with a large amount of rain in a short period of time is also increasing. Heavy rains generate a large amount of outflow in a short time, causing flooding in the downstream part of the mountainous area before joining the small and medium-sized rivers. In order to reduce damage to downstream areas caused by flooding, it is very important to calculate the outflow of mountainous areas due to torrential rains. However, the sewage network flooding analysis, which is currently conducting the most analysis in Korea, uses the time and area method using the existing data rather than calculating the rainfall outflow in the mountainous area, which is difficult to determine that the soil characteristics of the region are accurately applied. Therefore, if the rainfall is analyzed for mountainous areas that can cause flooding in the downstream area in a short period of time due to large outflows, the accuracy of the analysis of flooding characteristics that can occur in the downstream area can be improved and used as data for evacuating residents and calculating the extent of damage. In order to calculate the rainfall outflow in the mountainous area, the rainfall outflow in the mountainous area was calculated using MIKE SHE among the MIKE series, and the flooding analysis in the downstream area was conducted through MIKE 21 FM (Flood model). Through this study, it was possible to confirm the amount of outflow and the time to reach downstream in the event of rainfall in the mountainous area, and the results of this analysis can be used to protect human and material resources through pre-evacuation in the downstream area in the future.

• Korean Journal of Health Psychology
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• v.14 no.2
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• pp.277-292
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• 2009

This study investigated the responses of the autonomic nervous system of individuals with Type D personality during an acute stressful situation. Twenty-three female students of Type D personality and 23 female students with non-Type D personality. Stroop Color-Word Task was used to induce a stressful situation, heart rate variability (HRV) was used to measure the responses of the autonomic nervous system during the baseline, acute stress, recovery periods. To analyze the data, the repeated measures analysis of variance was used to compare the autonomic nervous system of the Type D group to that of the non-Type D group. Regression analysis is used to determine if the Type D scale and stress vulnerability predicted the activities of the autonomic nervous system during the baseline period. The results of this study demonstrated that the Type D group's normalized low frequency (LF norm) and ratio of low frequency to high frequency (LF/HF ratio) were higher than those for the non-Type D group, while its normalized high frequency (HF norm) was lower than that for the non-Type D group in all three periods. There were no statistically significant differences among the three periods in terms of LF norm, HF norm, and LF/HF ratio in the Type D group. The study demonstrated that the total scores of the Type DS-14 and scores of social inhibition and negative affect were independent predictors of LF norm and HF norm during the baseline. The Type D group showed increased activation of the sympathetic nervous system and/or decreased activation of the parasympathetic nervous system. These results support the hypothesis that the Type D personality is vulnerable to the stress. Also, the highly activated sympathetic and/or lowly activated parasympathetic nervous systems, which were observed in the Type D group during the baseline, indicated that the Type D individual is susceptible to psychosomatic disorders.

• Journal of Life Science
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• v.33 no.10
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• pp.797-807
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• 2023

To improve the functionality of mulberry, samples were fermented with Lactobacillus plantarum JCM 1149 (LP) or Pichia kudriavzevii Atz-EN-01 (PK), and their antioxidant and anti-obesity activities were compared to those of unfermented mulberry. After fermenting for 60 hr, the total polyphenol and flavonoid content of the PK-fermented mulberry (PKFM) and LP-fermented mulberry (LPFM) was 1.5-fold and 2-fold higher, respectively, while the total anthocyanin content was 1.3-fold and 1.5-fold higher in the PKFM and LPFM, respectively. DPPH radical scavenging activity was found to be 16.3% higher (86% vs. 100%) after PK fermentation and 8.1% higher (86% vs. 93%) after LP fermentation. The lipase inhibitory activity of the LPFM and PKFM was 62.9% and 52.5%, respectively. 3T3-L1 preadipocytes were treated with unfermented mulberry, LPFM, or PKFM at 200, 400, or 800 ㎍/ml and stained with oil-red-O. A slight difference in the staining was observed in samples treated with 400 ㎍/ml. However, treatment with 800 ㎍/ml significantly reduced staining compared to the control, and the LPFM exhibited relatively higher adipogenesis inhibitory activity than the PKFM. Blood triglyceride content increased by 9.5% in the high-fat diet group, but decreased by 17.1% in the control group, 37.1% in the LPFM group, and 41.6% in the PKFM group. The blood triglyceride content of the LPFM group decreased by 43.1% and 21.4% compared to the high-fat diet group and the control group, respectively, and that of the PKFM group decreased by 48.6% and 28.9% compared to the same groups. In conclusion, the results indicate that fermented mulberry has increased antioxidant activity, lipase inhibitory activity, and adipogenesis inhibition activity, and decreased blood triglyceride content compared to unfermented mulberry.